Plastic Ring Research Articles

EVALUATION OF LEFT VENTRICULAR REMODELING AFTER SURGICAL RECONSTRUCTION OF POSTINFARCTION ANEURYSM

Objective: To assess the effect of left ventricle reconstruction in patients with postinfarction aneurysm on remodeling and heart failure dynamics in the immediate and long-term postoperative period. Material and methods: 162 patients with IHD who underwent myocardial infarction and chronic left aneurysm were included in the study. All the patients underwent myocardial revascularization and reconstructive intervention in the LV cavity at the National Medical Research Center named after V.А. Almazov. Two groups of patients were formed, depending on the type of surgical intervention performed. Group 1 (n = 116) included patients who underwent linear plastic surgery of the left ventricle aneurysm. Group 2 (n = 46) identified patients who underwent an intraventricular plastic aneurysm of V. Dor. Results: In the early postoperative period, a statistically significant decrease in the volume of the LV cavity was observed and the global ejection fraction changed in both study groups. In patients with a significant degree of mitral insufficiency additionally did the plastic fibrous ring. The con ducted single-factor analysis showed a statistically significant effect of correction of mitral insufficiency on CDD, DAC, and global ejection fraction. The majority of patients in both groups experienced a decrease in LV volumes in the long-term period. Predictors of unfavorable clinical course of heart failure in the long-term period were revealed: violation of contractility at the level of basal parts of the left ventricle with a decrease in the index of violation of local contractility more than 3, ejection fraction less than 35%, uncorrected mitral insufficiency II and more, increased level of natriuretic peptide 4 times from the upper limit of the norm. Conclusions: Combined operation makes it possible to improve the contractive function of left ventricular, to reduce the degree of mitral insufficiency, the functional class of heart failure.

From La Ribera

From La Ribera John R. Sesgo (bio) Campoamor and Santiago de la Ribera lie an hour’s bicycle ride from each other. On Antonio’s mental map each town is enclosed by a red circle, and a line of the same color weaves in and out of dirt roads and bramble patches and cornfields to connect both places. The sea spreads a mile or two in the east, its blue edge unmixing with the coast. Near La Ribera, Antonio’s red line straightens along the banks of a small paved canal whose water does not move, but merely creases with the breeze, and shimmers burningly, like cooking oil. On hot days this section of map smells like the insides of a dead toad. Entering into either town, a black road swallows up the track and becomes smooth and efficient, only to lose its geometrical mind after a few miles and despair into a maze of one-way streets and end at a whitewashed house. At first glance, the house in Campoamor and the house in La Ribera look the same: each is a white box with a red roof, several windows, and a wooden door. Yet, if one looks closely — as one should with any map — one [End Page 74] sees the door to the house in Campoamor is tightly locked, and the curtains are pulled shut; while in La Ribera the same door stands ajar, letting out breakfast sounds and a dog’s demented barking, and the windows reveal friendly suntanned figures, one of whom, perhaps hearing someone enter, tucks a strand of blond hair behind her ear and turns her head. Antonio opens his eyes at precisely eight a.m. to a white ceiling. The room is as he left it last night, both curtains drawn back to let in the harsh summer sunlight, surfaces dusted, and every object lined up with the wall or floor or adjacent piece of furniture. Antonio’s bathing suit and sandals are already on, each hand palm-down and at the ready. Atop his dresser, under a grimacing crucifix, lie several objects: a bicycle lock key, a golden cross necklace, a chocolate bar, three one-hundred-peseta coins, and an elastic hair band. Avoiding a patch of squeaky springs, Antonio rolls out of bed and pockets all of these items except for the green hair band, which he sniffs and then carefully secretes beneath his underwear in the dresser’s top drawer. In the darkened hallway, his parents’ door is open a vigilant crack, from which come the stale smell of adult sleep and a raspy laboring of lungs. Antonio tiptoes past it and then down the carpeted stairs, through the living room and into the kitchen, where he pulls open the fridge and, in the coolly suspicious light, grabs a Coca-Cola. As he drinks, blurry scraps of dreams flow through his mind. His breakfast done, Antonio places the can deep in the garbage under the remains of yesterday’s dinner, and then, before closing the fridge, rotates the six-pack against the Leche Pascual to conceal the empty plastic ring. [End Page 75] Back in the living room, Antonio pauses to glance at the shapes that crouch everywhere like dark dwarfs given a night’s rest until their master’s waking. Suddenly, at the top of the stairs, Antonio sees his father in his robe, examining him gravely. His glasses are opaque, his lips like gashes. Antonio’s stomach cramps — but it’s just a shadow, they’re both still asleep in their room, the house is silent, it’s safe to leave. At the front door, Antonio double-checks his pocket’s contents, making sure the necklace and chocolate bar are there. Then, holding his breath, he turns the handle as gingerly as if it were fused to a dynamite pile underneath the house, and goes. Campoamor is empty and still this morning, the grass stiff as plastic. The sun is a hundred-watt bulb trained on Antonio as he wheels up its deserted streets, past its one bar and discotheque, past the three-star hotel. Soon he is skirting the highway — ahead, a car dwindles toward San Pedro...

Purple Nutsedge (Cyperus rotundus) Tuber Production and Viability Are Reduced by Imazapic

Weeds exploit underutilized space, causing economic losses in cropping systems. Weed management tactics alter that underutilized space until the crop can mature and efficiently use that space. One tactic is to reduce the weed propagules (e.g., seeds and tubers) that persist quiescently in the soil, which includes minimizing production and addition of new propagules to the soil. Purple nutsedge is a problematic weed around the globe, persisting between growing seasons as tubers in the soil. Imazapic is a peanut herbicide often used in Georgia for control of purple nutsedge. The objective of the experiment was to evaluate the effect of various rates of imazapic on purple nutsedge tuber production. Single presprouted purple nutsedge tubers were transplanted into outdoor microplots and treated after 6 wk of growth with six rates of imazapic (5 to 140 g ai ha−1) POST. A nontreated control was included. All emerged shoots at the time of application were marked with plastic rings; this allowed for classification of tubers at exhumation as (1) tubers attached to shoots that were emerged at time of application, (2) tubers attached to shoots that emerged after application, and (3) tubers without an aerial shoot during the study. At 7 wk after application, the tubers in the microplots were exhumed, classified, and quantified, and their ability to sprout was evaluated. In the nontreated control, there were 544 total tubers, with a log-logistic regression model describing the declining tuber population with increasing imazapic rate. The rate of imazapic that reduced total tuber population 50% (I50) was 36 g ha−1. In the nontreated control, there were 161 tubers attached to shoots that emerged, as when compared with plots that received an imazapic application that had an I50=60 g ha−1. Viability of purple nutsedge tubers was 44% at 70 g ha−1imazapic, suggesting the action of the herbicide may have rendered the tubers nonviable after new shoots were produced. The final classification of tubers included those that did not have an aerial shoot during the study. These were tubers in which apical dominance suppressed shoot development or were likely the most recent tubers to develop. Of the three classes, the tubers without shoots were the most prevalent in the nontreated control, with 358 tubers and an I50=18 g ha−1. Imazapic controls purple nutsedge foliage but also reduces the number of new tubers produced, and overall tuber viability and is a valuable tool in management of the long-term population density of this weed.

Hydration process and crack tendency of concrete based on resistivity and restrained shrinkage crack

Hydration process, crack potential and setting time of concrete grade C30, C40 and C50 were monitored by using a non-contact electrical resistivity apparatus, a novel plastic ring mould and penetration resistance methods, respectively. The results show the highest resistivity of C30 at the early stage until a point when C50 accelerated and overtook the others. It has been experimentally confirmed that the crossing point of C30 and C50 corresponds to the final setting time of C50. From resistivity derivative curve, four different stages were observed upon which the hydration process is classified; these are dissolution, induction, acceleration and deceleration periods. Consequently, restrained shrinkage crack and setting time results demonstrated that C50 set and cracked the earliest. The cracking time of all the samples occurred within a reasonable experimental period thus the novel plastic ring is a convenient method for predicting concrete’s crack potential. The highest inflection time (t i) obtained from resistivity curve and the final setting time (t f) were used with crack time (t c) in coming up with mathematical models for the prediction of concrete’s cracking age for the range of concrete grade considered. Finally, an ANSYS numerical simulation supports the experimental findings in terms of the earliest crack age of C50 and the crack location.

Variable Stiffness Fiber with Self-Healing Capability.

A variable stiffness fiber made of silicone and low melting point alloys quickly becomes >700 times softer and >400 times more deformable when heated above 62 °C. It shows remarkable self-healing properties and can be clamped, knitted, and bonded, as shown in a foldable multi-purpose drone, a wearable cast for bone injuries, and a soft multi-directional actuator.

Curing depth of a silorane-based resin composite

The silorane-based resin appears aiming to minimize the effects of polymerization shrinkage, but other properties must be studied. Objective: To evaluate the polymerization depth of two composites with different organic matrix. Material and methods:80 cylindrical specimens were prepared using a metallic matrix, with three layers (top, middle and bottom), 1 mm high and 5 mm in diameter. The specimens were divided into eight groups (n = 10) according to the composite resins: Filtek P90 (3M/ESPE); Filtek Z250 (3M/ESPE), light-cured with a LED device with different irradiance and times (600mW/cm2 x 40s, 1000mW/cm2 x 40s, 1000mW/cm2 x 20s; 1400mW/cm2 x 20s). The irradiance was controlled by placing plastic rings coupled to the device’s tip. Immediately after polymerization, the specimens’ layers were separated and five Knoop microhardness readings (initial hardness) were performed on each one of the four layers (0, 1, 2, and 3 mm). After 7 day storage in water at 37ºC, new readings were performed (final microhardness). The data were analyzed by four-way ANOVA (resin, energy density, depth and time) and Tukey test (α = 0.05). Results: The microhardness decreased with the depth increasing both in the initial and 7 day readings. The hardness increased with the highest power densities. The resin P90 had lower hardness values. Conclusion: The silorane-based resin showed Knoop microhardness values significant smaller than those of methacrylate-based resin in almost all evaluated parameters. However, both presented similar behaviors in relation to the curing depth.

New Fast Interaction Trigger for ALICE

The LHC heavy-ion luminosity and collision rate from 2021 onwards will considerably exceed the design parameters of the present ALICE forward trigger detectors and the introduction of the Muon Forward Tracker (MFT) will significantly reduce the space available for the new trigger detectors. To comply with these conditions a new Fast Interaction Trigger (FIT) will be built. FIT will be the main forward trigger, luminometer, and interaction-time detector. It will also determine multiplicity, centrality, and reaction plane of heavy-ion collisions. FIT will consist of two arrays of Cherenkov quartz radiators with MCP-PMT sensors and of a plastic scintillator ring. By increasing the overall acceptance of FIT, the scintillator will improve centrality and event plane resolution. It will also add sensitivity for the detection of beam-gas events and provide some degree of redundancy. FIT is currently undergoing an intense R&D and prototyping period. It is scheduled for installation in ALICE during 2020.

Hula Hoop in Fitness and the Centripetal Force

Since centuries ago or even more, the hula hoop has been practiced by people to keep their good health while having fun. Curiously, this simple toy made by a plastic ring, also previously made by a circle of willow, rattan, grapevines or stiff grasses, is subjected to several high and complex physical laws that make, at the same time, possible its beautiful movements. Physical laws are opposing and/or accompanying the movement of the circle-hoop-ring, such as gravity, centripetal force, friction, speed or velocity, and acceleration, in a torque or tendency to rotate. Specific muscles of the body are activated during hula hoop dancing and a general cardio exercise is happening. On the other hand, a stimulation of creativity is also occurring to make a mathematically reasonable and beautiful flow of movements for the own enjoyment or to make a performance for other people’s enjoyment. Then, the dancer with a hoop is moving the ring around several parts of his/her body (waist, core, shoulders, neck, arms), also rolling it over the body like a wheel, making waves in different axis, tossing it to the air or floor, etc. and dancer can jump him/herself through the hoop, or stealing its movements with his/her body. While motor learning happens, specific areas of the brain are activated differently during trials of learning. Then flow and fluid movements become automatic in an asymmetrical way considering our hand preference. However, for getting all this benefits, it is required a controlled practice in children and adults, that means a smooth and not violent, reasonable and measured practice in time and intensity and not negligent or irresponsible. Otherwise, some lesions have been described in literature.

Penile strangulation by polyvinyl chloride plastic pipe ring: Case report of sexual perversion

Penile constriction rings are either used for erotic or autoerotic purposes or to increase sexual performance. Various objects, both metallic and nonmetallic, can be used as constricting devices. Potentially, they can become irremovable, resulting in reduced blood flow, leading to edema and, sometimes, gangrene. We report an case of penile strangulation with a polyvinyl chloride (PVC) plastic pipe ring presenting as an urological emergency. It was removed with the help of a dental drill after failed attempts of the use of orthopedic instruments. Management of such cases can be challenging and removal of such objects requires the help of various orthopedic and dental instruments.

Design consideration for design a flat and ring plastics part using Solidworks software

Various considerations on design of plastic injection moulded parts were applied in initial stage to prevent any defects of end products. Therefore, the objective of this project is to design the plastic injection moulded part by taking consideration on several factors such as draft angle, corner radius and location of gate. In this project, flat plastic part, ring plastic part, core inserts for flat and ring plastic part were designed using SolidWorks software. The plastic part was drawn in sketching mode then the 3D modeling of solid part was generated using various commands. Considerations of plastic part such as draft angle and corner radius with location of gate was considered in the design stage. Finally, it was successfully designed the two plastic parts with their respectively insert by using SolidWorks software. The flat plastic part and ring plastic part were designed for the purpose for future researches for study the weld lines, meld lines, air trapped and geometrical size of the product. Thus, by designing the flat plastic part and ring plastic part having core insert on each part, the completed mould design of two plate mould can be considered. This is because, plastic injection parts are needed to be designed properly in order to neglect any defect when the mould was made.

CORR Insights(®): Are Complications Associated With the Repiphysis(®) Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

CORR Insights(®): Are Complications Associated With the Repiphysis(®) Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

Study Regarding the Influence of Polymerization Mode of Light Unit on Surface Microhardness of Composite Resins

The aim of the study was to compare the surface microhardness of composite resins polymerized in different mode of light unit. Three commercial composite resins: Charisma (Heraeus Kulzer Co.), Filtek Z 250 (3M ESPE Co.) and G-aenial Anterior (GC Company Co.), were used in this study. Fifteen samples of each material were obtained by placing the composite resin in plastic rings having 2 mm high and 6 mm inner diameter. All composite samples were cured using blue light-emitted diode G 0010 (SKI, China). Five samples were cured using ramp mode of the light unit, five samples were cured using single light: high intensity (constant) mode and five samples were cured using pulse mode. The samples were finished and polished and then stored in distilled water, at room temperature for 48 hours. The samples were subjected to microhardness evaluation using microhardness tester (Micro-Vickers Hardness System CV-400DMTM, CV Instruments Namicon). A 50 g load was applied through a Vickers indenter. For each sample three indentations were made in different areas of the sample and the value of Vickers hardness was calculated as a mean result of the three recordings. Statistical Mann-Whitney U test and Kruskal-Wallis test were used to compare the values of surface hardness. Polymerization of all three composite resins using pulse mode leaded to significantly lowest mean hardness values and single light high intensity mode to the highest values. Filtek Z250 composite resin showed the highest microhardness mean values in all three polymerization mode and Charisma the lowest values. Surface microhardness of composite resins is influenced by different modes of light unit. Single light high intensity mode of polymerization leaded to the highest values of microhardness, followed in descending order by ramp and pulse mode. The best results regarding the surface microhardness was recorded for Filtek Z250composite resin, followed in descending order by G-aenial Anterior and Charisma.

Influence of trickling liquid velocity and flow pattern in the improvement of oxygen transport in aerobic biotrickling filters for biogas desulfurization

AbstractBACKGROUNDBiological oxidation in biotrickling filters of high H2S loads contained in biogas streams still requires further study to reduce elemental sulfur accumulation due to limited gas–liquid oxygen mass transfer inside biotrickling filter beds. Reduction of elemental sulfur accumulation may be improved by regulating the main manipulated variables related to oxygen mass transfer efficiency during biological hydrogen sulfide removal in biotrickling filters.RESULTSTrickling liquid velocity and co‐current flow were selected as the most appropriate manipulated variable and flow pattern configuration compared with manipulating the air supply flow rate and a counter‐current flow pattern in order to improve gas–liquid oxygen mass transfer in abiotic conditions. The influence of trickling liquid velocity on the performance of a lab‐scale biotrickling filter treating high loads of H2S in a biogas mimic and operating in co‐current flow at neutral pH and packed with plastic pall rings was investigated.CONCLUSIONSThe effect of trickling liquid velocity modulation between 4.4 and 18.9 m h−1 in biotrickling filter performance was compared with operation without trickling liquid velocity regulation. Velocity regulation resulted in an improvement of 10% in the elimination capacity and, most importantly, a 9% increase in product selectivity to sulfate at a loading rate of 283.8 g S‐H2S m−3 h−1. Concentration profiles along the biotrickling filter height evidenced that trickling liquid velocity regulation progressively led to better dissolved oxygen distribution and, thus, enhanced overall biotrickling filter performance. © 2015 Society of Chemical Industry

Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

Previous studies measured the effects of 222Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222Rn gas, which was in the order of 0.5 nSv Bq−1 m3 d−1.

Low incidence of leg and foot injuries in colour-ringed Marsh Tits Poecile palustris

Marking birds with individually identifiable metal leg-rings (bands) is a common research tool, and the additional use of plastic colour rings has facilitated numerous studies of bird ecology, yet there is limited information for the impact of these methods on individuals and populations. Despite generally being considered to have a negligible effect upon birds, recent literature shows that leg rings can cause injuries to some passerines. This creates an ethical problem and may also bias research results by influencing individual behaviour and survival. The incidence of leg injuries was monitored on colour-ringed and unringed Marsh Tits Poecile palustris over 12 years. The overall incidence of permanent injury did not differ between ringed and unringed birds, but six of 404 colour-ringed birds (1.5%) carried a leg or foot injury, which was significantly greater than the background rate (0.2%) among 515 unringed birds. Some injuries on ringed birds were temporary or may have been unrelated to the rings; however, one fatality and two serious injuries were recorded, probably resulting from colour rings becoming caught on thorns or other objects. Although ring-related injuries were very rare, it is recommended that ringers studying Marsh Tits try to minimise the number of rings on each leg.

Vibration Characteristics for Planetary Geared Systems with Plastic Gears

A torsional dynamic model and testing model for planetary geared systems are established to study the effects on its vibration characteristics as substituting plastic gears for steel ones successively. The dynamic model is solved by using variable step Runge-Kutta method and the vibration testing experiments for four kinds of combined planetary geared systems are carried out under different rotation speed and load torque. The numerical and experimental results show that the high frequency spectra are suppressed effectively as substituting plastic gears for steel ones. The gear mesh dynamic load and vibration intensity caused by the meshing fundamental frequency and side-frequency reduce markedly when the plastic ring and planet gear substitute for steel ones together. The numerical simulations have a better consistency with the experimental results, which verifies the correctness of the conclusions.

Use of the “O” Wound Protector/Retractor in Extremely Obese Pregnant Woman - An Unexpected Event

Background: Extremely obese pregnant women are a rapidly increasing group requiring obstetrical care. When surgical delivery is indicated they present a unique challenge. Case: We submit the case of a pregnant woman with a body mass index (BMI) of 63Kg/m² (385 pounds) with a reduced pelvic outlet who selected to deliver by primary cesarean. A sub umbilical Joel Cohen incision was selected. The surgical procedure and delivery were uneventful. Twelve hours post-surgery a circumferential area of skin redness was present in the area where the wound protector-retractor was placed. We believe this represented an area of relative ischemia created by the pressure between the two plastic rings of the device. There was no pain or inflammation, the area returned to normal within 48 hours. Conclusion: We are not aware of a similar case reported with the use of this device. Practitioners are alerted to this event and reminded that the deployment of the device must be carefully performed to avoid this possible deleterious effect.

Improved source path localisation in ring applicators and the clinical impact for gynecological brachytherapy.

PurposeThe path of subsequent dwell positions of an afterloader source being moved through a ring applicator for cervix cancer brachytherapy deviates from an ideal circle and the position of marker wires. This can lead to deviations of several millimetres between real and assumed dwell positions for treatment planning with simplified source path models. The aim of this study was to test video- and autoradiography-based methods for source path determination, and to study the influence of dwell position accuracy on dose-volume histogram (DVH)-parameters.Material and methodsVideos of the exact motion of the source wire through three different (r = 26, 30, 34 mm) computed tomography/magnetic resonance (CT/MR) compatible plastic ring applicators were recorded. Observed dwell positions covering the whole length of each applicators channel were used to adjust the circular source path model. The agreement of the true source positions derived from video analysis with those of the corrected circular source path was verified using autoradiography. The impact of an accurate source path definition on dose planning was analysed by simulating clinically relevant uncertainties in 10 clinical treatment plans.ResultsDepending on the ring size, source path diameters had to be increased by 0.5-1.0 mm in order to achieve acceptable maximum differences between observed and corrected dwell positions (1.3-2.0 mm). Autoradiography analysis showed a positional accuracy within ± 3 mm (extended standard deviation k = 2). For shifts of ± 2.5 mm for even all dwell positions, the systematic and random variation of the D2cm3 for bladder, rectum, and sigmoid was within 3%, while the impact on DVH uncertainties was much smaller for clinical target volume (CTV)HR and gross tumour volume (GTV).ConclusionsIt is strongly advised to verify the real source path for ring applicators during acceptance testing in order to assure accurate source path definition and dose planning. Autoradiography can be used for source path verification with acceptable accuracy for treatment planning and dose reporting.

Halosulfuron Reduced Purple Nutsedge (Cyperus rotundus) Tuber Production and Viability

Weeds persist and cause economic losses in agricultural systems because they exploit underused portions of that system. Reducing the effect of weeds on agroecosystems begins with minimizing the number of propagules (e.g., seeds and tubers) that are produced and returned to the soil. Purple nutsedge is a problematic weed around the globe, persisting between growing seasons as tubers in the soil. Halosulfuron is an effective herbicide for controlling purple nutsedge foliage and is used in corn and several vegetable crops. Studies were conducted to evaluate the effect of various rates of halosulfuron on purple nutsedge tuber production. Single, presprouted purple nutsedge tubers were transplanted into outdoor microplots and treated after 6 wk of growth with six rates of halosulfuron (7 to 208 g ai ha−1) POST with a nontreated control (NTC). All shoots that had emerged at the time of application were marked with plastic rings; this allowed for classification of tubers at exhumation of (1) tubers attached to shoots that had emerged by the time of application, (2) tubers attached to shoots that emerged after application, and (3) tubers without an aerial shoot during the study. Seven weeks after application, the tubers in the microplots were exhumed and tubers were classified, quantified, and their ability to sprout was evaluated. In the NTC, there were 530 total tubers, with a log-logistic regression model describing the tuber population with increasing halosulfuron rate. The rate of halosulfuron that reduced total tuber population 50% (I50) was 8 g ha−1. In the NTC, 200 tubers were attached to shoots that emerged following halosulfuron application, and this class of tubers had anI50of 19 g ha−1. Viability of tubers with shoots that emerged following halosulfuron application was 28% at the 52 g ha−1halosulfuron, suggesting the action of the herbicide may have rendered the tuber nonviable after new shoots were produced. The final classification of tubers was those that did not have an aerial shoot during the study. These were tubers in which apical dominance suppressed shoot development or were likely the most-recent tubers to develop. Of the three classes, the tubers without shoots were the most numerous in the NTC, with 294 tubers and anI50of 1 g ha−1. Halosulfuron is an effective herbicide that not only controls purple nutsedge foliage but also reduces the number of new tubers produced and overall tuber viability. This could be an important component to reduce the long-term population density of the weed.

Auxin Concentration Affects Adventitious Rooting of Mound Layered Caddo Sugar Maple (Acer saccharum) and Shantung Maple (Acer truncatum)

Stump sprouts of stooled caddo sugar maple (Acer saccharum Marsh. subsp. saccharum) (caddo maple) and shantung maple (A. truncatum Bunge) were propagated by mound layering. In early summer, shoot bases were wounded and treated with 0, 10,000, 15,000, or 20,000 ppm (0, 1.0, 1.5, or 2.0%) indole-3-butyric acid (IBA) dissolved in 50% ethanol or 0, 5,000, or 10,000 ppm (0, 0.5, or 1.0%) of the potassium (K) salt of IBA (K-IBA) dissolved in water. Shoot bases were covered with a commercial growing substrate containing bark, Sphagnum peat moss, and perlite and retained by plastic rings 38 cm (15 in) in height. Rooted shoots were harvested in fall or late winter. Auxin concentration influenced rooting of caddo maple and shantung maple mound-layered shoots. Rooting peaked at 15,000 ppm (1.5%) IBA for both caddo maple (71%) and shantung maple (34%). Mean root number for caddo maple, but not shantung maple, increased as IBA concentration increased. Differences in mean root length were not significant. Results suggest caddo maple can be successfully propagated by mound layering. For shantung maple propagation, mound layering was less successful, so alternatives such as stem cuttings should be considered.